Please help me with a Re-build ^^

K so I think something has happened to my Motherboard in my second computer... and rather then just ditch it, I'd like to re-use as many parts as I can ^^

So if you could, please help me pick out a new Motherboard, I would also like to get a new case cause the one I have is just way too big. I know how to change many parts in a computer, but I've never really messed with a motherboard (or power supply) but I would really like to re-build this one as best I can ^^ If you have any videos or stuff that could help, please post these as well (I could always watch them on my main computer while re-building the old one) ^^

Edit: I think I might need to add a new harddrive as well actually.

Here's what in the downed computer right now:

Intel Core 2 Duo E6700 Dual Core Processor LGA775 Conroe 2.67GHZ 1066FSB 4MB Retail
XFX Radeon HD 5750 700MHZ 1GB 4.6GHZ GDDR5 2XDVI HDMI Display Port DIRECTX11 PCI-E Video Card
OCZ SLI-Ready Dual Channel 4096MB PC6400 DDR2 800MHz Memory (2x2048MB) (8 gigs total tho)
Liteon DVD+RW 20X8X16 DVD-RW 20X6X16 DL 8X Lightscribe INT IDE Drive Black DVD Writer OEM
Seagate Barracuda 7200.10 500GB SATA2 3GB/S 7200RPM 16MB Cache NCQ Hard Drive
Thermalright ULTRA-120 Extreme 6 Heatpipe Cooler LGA775 Heatsink
EVGA Nforce 680I SLI LGA775 Conroe ATX DDR2 2PCI-E16 2PCI SATA2 Sound GBLAN 1394 Motherboard
OCZ GameXStream 700W ATX12V 24PIN SLI Ready Active PFC ATX Power Supply 120MM Fan Black
Microsoft Windows Vista Home Premium Edition 64BIT DVD OEM
Creative Sound Blaster X-FI Xtreme Audio 24BIT Sound Card 7.1 PCI OEM
Thermaltake VA8003BWS Black ATX Tower Case 10X5.25 2X3.5 6X3.5INT No PS 25CM Fan Window